Water & Major Minerals

Water is (2 forms)

Intracellular and extracellular fluid

Water as Intracellular fluid

Fluid within the cells, usually high in potassium & phosphate

Water as extracellular fluid

Fluid outside the cells, about 1/3 of body water, includes interstitial fluid

Interstitial fluid

pertains to extracellular fluid, high in sodium & chloride

Water functions

carries nutrients/waste products, maintains structure of proteins & glycogen, participates in metabolic reactions, small molecule solvent, maintains blood volume, lubricant/cushion,regulates body temperature

Water balance

60% BW Adult, higher for children, 75% of weight in lean tissue, less than 25% of adipose tissue, lower in females, obese, elderly for lack of LBM

Thirst & satiety

thirst sensed by mouth, hypothalamus, and nerves. Water intake inadequate→blood concentrates/thickens→ dry mouth & hypothalamus send message to drink

What happen when too much water is taken?

stretch receptors in stomach signal to stop drinking. Heart receptors signal to stop drinking as blood volume increases

Dehydration

water output exceeds water input. symptoms: thirst, dry skin/mucous membranes, rapid heartbeat, low blood pressure/weakness

Water intoxication

too much water, caused by excessive water intake or kidneys lacking in urine production creating hyponatrmia: Hypo(low)natr(sodium)mia(blood), symptoms: confusions, convulsions, death

Sources of H20

-Fruits & vegetables up to 90% H20
-Generated during metabolism
-Average daily total intake 2.5 L

losses of H20

500 ml obligatory water to make urine to carry away waste, lungs as vapor, sweat, feces, 2.5L average daily loss

Water Adequate Intakes

Men, 3.7 liter/day, women 2.7 liter/day

1 mL/kcal most adults, 1.5 mL/kcal most athletes

Blood volume/pressure(samething)

Fluids maintain blood volume, which influences blood pressure, controlled by antidiuretic hormone(ADH)/Vasopressin, renin, angiotensin and aldosterone

Kidneys and Blood Volume/pressure

Kidneys make urine, ridding waste and reabsorbing required substances

Vasopressin/ADH

water conserving hormone, hypothalmus signals pituitary to release ADH when blood volume/pressure too low or extracellular fluid is too concentrated

Renin

kidney releases renin if body pressure is too low, it raises blood volume/pressure

angiotensin

Vasoconstrictor: hormone involved in blood pressure regulation

renin hrydrolyzes angiotensinogen(blood protein) to …

angiotensin I

angiotensin-converting enzyme

converts angiotensin I to angiotensin II, increasing blood pressure

Angiotensin stimulates the release of ________ from the adrenal glands

aldosterone

________signals kidneys to excrete more K & retain more Na & therefore H20

Aldosterone

Dissociation of salt in H20

When a mineral salt dissolves in water it dissociates into ions: anions (-) & cations (+)

electrolytes

salts that dissociate into ions

mEq

concentration of electrolytes in a volume of solution

located outside & inside cell

Outside cell: Na(sodium) & CI

Inside cell: K, Mg(potassium), Phosphate & sulfate

Osmosis

Movement of H20 across membrane toward the side
where the solutes are more concentrated.

Proteins & fluids & ion flow

-attract water

-regulate passage of substances

• (-) ions follow (+) ions

-water flows to more concentrated solution

Fluid & Electrolyte Balance

controlled by GI tract & kidneys, regulate amount of minerals in the body

Kidney

control water content, regulate electrolyte content through adrenal gland, K+ excreted to maintain balance

causes of Fluid & Electrolyte Imbalance

severe prolonged vomiting, diarrhea, heavy sweating, burns, traumatic wounds

replacing lost fluids and electrolytes

-Fluids and food in mild cases, ORT (oral rehydration therapy): 1/2 L boiling water, 4 tsp sugar, ½ tsp of salt

Ions regulate pH bodily fluids, define low and high pH

High pH: greater than 7 alkaline

low pH:less than 7 acidic

Buffers in the blood

acid base balance controller, keep a solution’s pH constant when acids or bases
are added, these are: Bicarbonate (base HCO3), Carbonic acid (H2C03) and proteins

respiration in the lungs

acid base balance controller.

CO2 forms carbonic acid in blood.

carbonic acid too great→ increased respiration→ more C02 exhaled

Bicarbonate too great→ slowed respiration → more C02 retained, forming carbonic acid

Excretion by Kidneys

acid base balance controller.

either retains or excretes ions(bicarbonate), urine acidity fluctuates

buffers

can neutralize acids or bases

major & minor minerals needed

Major: > 100mg/day

Minor: < 100mg/day

Inorganic minerals

retain chemical identification(do not change), not destroyed by heat,air,acid,mixing, leaches into cooking H20

foods can contain______ which prevent absorption, ex: phylates & oxalates

binders

Nutrients can alter absorptions of one another example

Ca excreted w high Na intake

Sodium

functions: principal cation of extracellular fluid, regulator of extracellular volume, acid base balance, nerve transmission & muscle contraction.

absorbed in GI tract, freely travels in blood, excreted & reabsorbed by kidneys

UL: 2300mg

AI: 1500mg

those with______ are at increased risk for hypertension(HTN) with Na intake

Chronic kidney disease, DM, Those already with HTN, African Americans, Age > 40; Age > 51, Overweight

Dash Diet

-diet to stop hypertension, reduces BP

-low sodium and all fats. high in calcium, potassium, and magnesium

-includes whole grains, fruits, veggies, fish, poultry, legumes

high Na intake leads to…

high calcium excretion

Sodium is lost via…

vomiting, Diarrhea, heavy sweating

Na/Sodium toxicity

edema, hypertension

Chloride (CI-)

anion of extracellular fluids, occurs with Na, freely moves across membranes, maintains fluid & electrolyte balance, part of hydrochloric acid, abundant in foods- especially processed

Potassium(K+)

principal intracellular cation, maintains fluid & electrolyte balance, cell integrity, nerve transmission, muscle contraction/heartbeat. abundant in fresh foods, AI= 4700mg, K+ rich foods reduce risk of stroke

low K+ diet leads to…

HTN and increased risk of heart disease

High K+, low Na+ diet…

prevents and corrects HTN

Potassium (K+) deficiency

most common electrolyte imbalance, results in HTN, salt sensitivity, kidney stones and bone turnover, irregular heartbeat, muscle weakness and glucose intolerance, caused by: diabetic acidosis, dehydration, prolonged vomiting & diarrhea, Drugs/laxatives

Potassium (K+) toxicity

cannot occur from foods but from overconsumption of K+ salts/supplements, kidneys accelerate excretion, K+ vein injection can stop heart, disease(renal failure)

Calcium

most abundant mineral in body, 99% in bones/teeth-becomes calcium bank for blood

Mineralization

Ca, phosphorus & other minerals crystallize on collagen matrix of growing bones, hardening them

remodeling

gaining & losing minerals at all times

Ca in body fluids

1%, blood pressure maintenance, muscle contraction, blood clotting, Transmission of nerve impulses, Secretion of hormones, Activation of some enzyme reactions, Activates calmodulin(calcium-binding protein regulates muscles)

Ca Balance

Maintained system or hormones and Vitamin D; response to alterations by intestines, bones and kidneys

Vitamin D

Enhances Ca absorption in intestines, Stimulates osteoclasts to break down bones

Calcitonin

thyroid gland hormone that regulates blood Ca, lowers it when levels are too high

Parathyroid Hormone (PTH)

Parathyroid gland hormone that regulates blood calcium by raising it when it falls too low, stimulates action of Vit D

calcium rigor

Blood levels > normal, Muscles contract &n cannot relax, Hardness or stiffness of
muscles

Calcium tetany

Blood levels < normal, Uncontrolled muscle contraction or spasms

Ca absorption

30% of indigested Ca absorbed, Vit D makes Ca-binding protein, when body demands more, body increases absorption

Ca absorption enhancers

Stomach acid, Vitamin D, Lactose (in infants),Growth hormones

Ca absorption inhibitors

Lack of stomach acid, Vitamin D deficiency, High phosphorus intake, High-fiber diet, Phytates(Seeds, nuts, grains), Oxalates(Beet greens, rhubarb, spinach, sweet potatoes)

Ca food sources

Tofu, Corn tortillas, Almonds, Sesame seeds, Mustard & turnip greens, bok choy, kale, parsley, watercress, broccoli, Seaweed, Fish with bones, Oysters

Ca deficiency/loss

can be caused by high intakes of Na & protein

peak bone mass

the highest attainable bone density for an individual, developed during the first three decades of life, teens/20’s -35ish

calcium toxicity

UL: 2500mg, 2000mg adults 50+, constipation, increased risk of urinary stone formation, kidney dysfunction

when calclum intake is low blood still manages to contiain its Ca needs, how?

calcium is taken out of the bones

Ca recommendations

-1300 mg/day for teens, 1000 mg/day adults up to 50, 1200 mg/day for women 50+ and men 70+

Phosphorus

2nd most abundant mineral in body, 85% bound with Ca in bones & teeth, buffer system, DNA & RNA, Energy metabolism, phospholipids (structural/transportational)

Magnesium

> ½ bones, remainder in muscles/soft tissue, 1% extracellular fluid, Bone health, Energy metabolism, Aids in making proteins, Enzyme systems, Muscle contractions, Blood clotting, Immune fx, Protects against HTN
• ATP metabolism

Magnesium intake/sources

osteoporosis, inflamation, chronic disease risk, growth failure, found in legumes, nuts, whole grains, seeds chocolate, cocoa

Mg toxicity

rare, only from supplements, diarrhea, alkalosis, dehydration

sulfate

Salt produced from oxidation of sulfur, Occurs in essential
nutrients: Methionine & Cysteine, skin, hair, nailsm deficiencies do not occur when diets contain protein